Whenever
you can, learn from the historical sources. People in the past had fought
for their life and developed highly sophisticated techniques.

Speed is
not everything. Timing and distance are more important. Example below:

From
left to right, Patrick (left hand side) struck first and fast.
Lancelot
(right hand side) leaned backward to void the strike just by an inch,
showing confidence in timing and distancing.

Lancelot then counter struck at
Patrick once the opponent was unable to move just after the strike.

Hit the closest targets available. It often leads to fingers and legs. No
fingers = no weapon holding ability. No legs = no standing (kneeing-down
will only stretch the muscles wider and enlarge the wound) = no fight.
Example below:

When the
opponent has the longer weapon, fight close by rushing in. When the opponent
has the shorter weapon, fight far by keeping distance. Example below:

In
another fight, Patrick started by rushing and striking simultaneously. This
time Ben had learned the lesson and stayed out of range to make better use
of his longer weapon.

Ben
voided Patrick's first attack and then countered by cutting at Patrick's
forearm.

Thrusts
can be surprisingly fast and launched at the unaware opponent with good
effect. If you are good at it, you may be able to stop a lot of incoming
attacks before they were fully launch by thrusting at the weapon-wielding
hand.

Unarmed
hand is faster than armed hand due to the lack of loading, but shorter in
reach. Be sure to put your offhand in use when you are holding your weapon
with single hand.

In group
battle, some moves are not feasible without hitting your teammates.
Formation fighting is different from 1 on 1 dueling. Stay tight and fight as
a group are more important than individual skill.

When
fighting against multiple opponents, some moves that work in 1 on 1 dueling
are not desirable because they would open you up for the opponents' counter
attack.

You may
discover more tips along with your sparring. Happy playing and learning.
Good luck!